Keyed brake disk assembly

ABSTRACT

Friction disks, such as rotors and stators, including keyed wear liners are disclosed. The friction disks may include a core and a replaceable wear liner coupled to each side of the core. The wear liners may include a plurality of keys which engage key notches in the core. The key notches may prevent the wear liners from rotating with respect to the core in response to a shear force, such as a force applied during braking.

FIELD

The present invention relates to aircraft braking systems. Inparticular, the invention relates to a brake disk assembly of anaircraft braking system.

BACKGROUND

Aircraft brake systems typically employ a series of friction disksforced into contact with each other to stop the aircraft. Friction diskssplined to a non-rotating wheel axle are interspersed with frictiondisks splined to the rotating wheel. The friction disks withstand anddissipate the heat generated from contact between one another duringbraking. During high speed landings and rejected takeoffs (“RTOs”), theamount of heat generated can be enough to destroy friction disks made offormerly commonly used materials, such as steel. Carbon compositematerials are better suited for high temperature use and are now thestandard for friction disks in aircraft brake assemblies. However,carbon composite disks can be expensive to manufacture, especially oneshaving the thickness preferable for use on an aircraft. Replaceable wearliners may be bonded to a core in order to decrease costs. However, suchliners may delaminate from the core due to the high shear force duringbraking in combination with high braking temperatures.

SUMMARY

According to various embodiments, a stator is disclosed. The stator maycomprise a core and a wear liner. The core may comprise a spine and aninner core having a thickness greater than the spine. The inner core mayfurther comprise a key notch recessed into an outer portion of the innercore. The wear liner may be coupled to the spine. The first wear linermay comprise an annular ring and a stator key. The stator key may matewith the key notch in the inner core. The stator key may engage a corekey in the inner core to prevent rotation of the first wear liner.

According to various embodiments, a rotor is disclosed. The rotor maycomprise a core and a wear liner. The core may comprise a spine and aplurality of lugs. At least one lug may comprise a recessed key notch.The wear liner may comprise an annular ring having a wear surface and amating surface. The mating surface may be disposed adjacent to thespine. The wear surface may also comprise a rotor key. The rotor key maybe disposed within the recessed key notch. The rotor key may contact theat least one lug to oppose a shear force applied to the wear liner.

According to various embodiments, a friction disk is disclosed. Thefriction disk may comprise a core and a wear liner. The core maycomprise a spine and a plurality of lugs. The plurality of lugs may havea plurality of notches recessed therein. The wear liner may comprise awear surface, a mating surface, and a plurality of keys located adjacentto at least one of an inner surface and an outer surface of the wearliner, wherein the plurality of keys are located within the plurality ofnotches.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the drawing figures, wherein like numeralsdenote like elements.

FIG. 1 illustrates, in accordance with various embodiments, multi-diskbrake;

FIG. 2 illustrates, in accordance with various embodiments, aperspective view of a stator having a keyed wear liner;

FIG. 3 illustrates, in accordance with various embodiments, a cutawayview of a stator having a keyed wear liner;

FIG. 4 illustrates, in accordance with various embodiments, an explodedview of a rotor having a keyed wear liner;

FIG. 5 illustrates, in accordance with various embodiments, an assembledrotor having a keyed wear liner; and

FIG. 6 illustrates, in accordance with various embodiments, a rotor witha keyed wear liner that partially extends into rotor lugs.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration and their best mode. While these exemplary embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the inventions, it should be understood that other embodimentsmay be realized and that logical, chemical, and mechanical changes maybe made without departing from the spirit and scope of the inventions.Thus, the detailed description herein is presented for purposes ofillustration only and not of limitation. For example, the steps recitedin any of the method or process descriptions may be executed in anyorder and are not necessarily limited to the order presented.Furthermore, any reference to singular includes plural embodiments, andany reference to more than one component or step may include a singularembodiment or step. Also, any reference to attached, fixed, connected orthe like may include permanent, removable, temporary, partial, fulland/or any other possible attachment option. Additionally, any referenceto without contact (or similar phrases) may also include reduced contactor minimal contact.

Friction disks, including rotors and stators, including keyed wearliners are disclosed. The friction disks may include a core and areplaceable wear liner coupled to each side of the core. The wear linersmay include a plurality of keys which engage key notches in the core.The key notches may prevent the wear liners from rotating with respectto the core in response to a shear force, such as a force applied duringbraking.

Referring to FIG. 1, a multi-disk brake system 20 is illustratedaccording to various embodiments. The system may include a wheel 10supported for rotation around axle 12 by bearings 14. Wheel 10 includesrims 16 for supporting a tire (not shown), and a series of axiallyextending rotor splines 18 (one shown). Rotation of wheel 10 ismodulated by disk brake system 20. Disk brake system 20 includes torqueflange 22, torque tube 24, a plurality of pistons 26 (one shown),pressure carbon disk 30, and end plate 32. Torque tube 24 is anelongated annular structure that includes reaction plate 34, and aseries of axially extending stator splines 36 (one shown). Reactionplate 34 and stator splines 36 may be integral with torque tube 24 asshown in FIG. 1, or attached as separate components.

Disk brake system 20 also includes a plurality of friction disks 38. Theplurality of friction disks 38 includes at least one non-rotatablefriction disk 40, also known as a stator, and at least one rotatablefriction disk 42, also known as a rotor. Non-rotatable friction disks 40may comprise a stator core 48 and stator wear liners 50. Rotatablefriction disks 42 may comprise a rotor core 49 and rotor wear liners 60.Each friction disk 38 includes an attachment structure. In theembodiment of FIG. 1, each of four non-rotatable friction disks 40include a plurality of stator lugs 44 at circumferentially spacedpositions around non-rotatable friction disk 40 as an attachmentstructure. Similarly, each of five rotatable friction disks 42 include aplurality of rotor lugs 46 at circumferentially spaced positions aroundrotatable friction disk 42 as an attachment structure. In the embodimentof FIG. 1, pressure carbon disk 30, end plate 32, and friction disks 38are all annular structures made at least partially from a carboncomposite material.

Torque flange 22 is mounted to axle 12. Torque tube 24 is bolted totorque flange 22 such that reaction plate 34 is near an axial center ofwheel 10. End plate 32 is connected to a surface of reaction plate 34facing axially away from the axial center of wheel 10. Thus, end plate32 is non-rotatable by virtue of its connection to torque tube 24.Stator splines 36 support pressure carbon disk 30 so that pressurecarbon disk 30 is also non-rotatable, Stator splines 36 also supportnon-rotatable friction disks 40. Non-rotatable friction disks 40 engagestator splines 36 with gaps formed between stator lugs 44. Similarly,rotatable friction disks 42 engage rotor splines 18 with gaps formedbetween rotor lugs 46. Thus, rotatable friction disks 42 are rotatableby virtue of their engagement with rotor splines 18 of wheel 10.

As shown in FIG. 1, rotatable friction disks 42 are arranged with endplate 32 on one end, pressure carbon disk 30 on the other end, andnon-rotatable friction disks 40 interleaved so that rotatable frictiondisks 42 are adjacent to non-rotatable friction components. Pistons 26are connected to torque flange 22 at circumferentially spaced positionsaround torque flange 22. Pistons 26 face axially toward wheel 10 andcontact a side of pressure carbon disk 30 opposite rotatable frictiondisks 42. Pistons 26 may be powered electrically, hydraulically, orpneumatically.

Referring to FIG. 2, a stator 40 is illustrated according to variousembodiments. Stator 40 may comprise a stator core 48, and stator wearliners 50. Stator core 48 and stator wear liners 50 may comprisedifferent materials. For example, in various embodiments, stator core 48may comprise steel, and stator wear liners 50 may comprise a carboncomposite. However, in various embodiments, stator core 48 and statorwear liners 50 may comprise the same material, such as a carboncomposite. In various embodiments, the material of stator core 48 may beselected for its structural properties. For example, stator core 48 maycomprise silicon carbide or titanium. A material of stator wear liners50 may be selected for its frictional properties. In variousembodiments, the material of stator wear liners 50 may be selected forits wear resistance, thermal conductivity, heat capacity, structural,and/or oxidation resistance properties. Thus, stator 40 may contain thestructural advantages of stator core 48, and the frictional advantagesof stator wear liners 50.

Stator core 48 may comprise spine 202 and inner core 204. Inner core 204may comprise stator lugs 44. Inner core 204 may further comprise gaps210 between an inner portion of stator lugs 44. Gaps 210 may be locatedto align with stator splines 36. The engagement between the statorsplines 36 and stator lugs 44 prevents stator 40 from rotating when atorque is applied to stator 40 during braking. Stator core 48 mayfurther comprise core keys 244 and core key notches 246 located at anouter portion of stator lugs 44. In various embodiments, core keys 244may extend radially from an outer portion of inner core 204. In variousembodiments, core keys 244 may comprise teeth. Core key notches 246 maybe a recess between core keys 244, and/or a recess in an outer portionof inner core 204.

Stator wear liners 50 may be located adjacent to stator core 48. Asillustrated, stator wear liners 50 may be located adjacent to oppositesides of spine 202. In various embodiments, stator wear liners 50 may becoupled to stator core 48. Stator wear liners 50 may be coupled tostator core 48 by, for example, a bond or by mechanical fastening suchas riveting. In various embodiments, a bond may comprise an adhesivecapable of maintaining adhesion under high temperatures, for example,between about 800° F. (about 426° C.) and 2000° F. (about 1093° C.). Inaddition, in various embodiments, an adhesive may be applied viachemical vapor deposition. In various embodiments, stator wear liners 50are not fastened to stator core 48, and stator wear liners 50 are keptin place by contact from adjacent components, such as rotor wear liners60. In various embodiments, stator wear liners 50 may be replaceablewear liners, such that after stator wear liners 50 have been worn belowa suitable operation thickness, stator wear liners 50 may be detachedfrom stator core 48 and replaced by new or remanufactured wear liners.In various embodiments, used stator wear liners may be bonded togetherto form a remanufactured stator wear liner. Stator wear liners 50 maycomprise stator annular ring 252 and stator keys 254. In variousembodiments, stator wear liners 50 may comprise a substantially uniformthickness. However, in various embodiments, stator keys 254 may have athickness which is greater than or less than a thickness of statorannular ring 252. Stator keys 254 may be separated by stator wear linerkey notches 256. In various embodiments, stator annular ring 252 andstator keys 254 may be a single continuous component. However, invarious embodiments stator keys 254 may be coupled to stator annularring 252. In various embodiments, stator keys 254 may be sized andshaped to mate with core key notches 246. In various embodiments, corekeys 244 may be sized and shaped to mate with wear liner key notches256.

During aircraft braking, a torque may be applied to stator wear liners50. The torque may cause a shear force that, in the absence of acounteracting force, acts to rotate stator wear liners 50 relative tostator core 48. However, core keys 244 may slide into wear liner keynotches 256 to engage stator keys 254. Contact between core keys 244 andstator keys 254 may counteract the torque, thus reducing the shearforce, and may prevent stator wear liners 50 from rotating relative tostator core 48. In various embodiments, whether by design or due tomanufacturing tolerances, small gaps may exist between core keys 244 andwear liner key notches 256, resulting in stator wear liners 50 rotatingslightly relative to stator core 48 prior to core keys 244 engagingstator keys 254. In various embodiments, although core keys 244 mayprevent rotation of stator wear liners 50, due to elastic materialproperties of stator wear liners 50, stator wear liners 50 may stretchin the direction of the torque at an outside diameter of stator wearliners 50 due to the shear force.

Referring to FIG. 3, a cutaway view of stator 40 is illustratedaccording to various embodiments. Stator 40 may comprise stator core 48,stator lugs 44, gaps 210, stator wear liners 50, stator annular ring252, and stator keys 254. As illustrated in FIG. 3, a cross-section ofcore spine 202 may be substantially rectangular such that stator wearliners 50 are substantially parallel. However, in various embodiments, across section of core spine 202 may be triangular, such that stator wearliners 50 are non-parallel and in a Belleville configuration. In aBelleville configuration, stator wear liners 50 may comprise a coneddisc shape such that a distance between stator wear liners 50 decreasesas the radius increases.

In various embodiments, stator wear surface 320 may begin at a greaterradius than stator keys 254. Thus, stator keys 254 may not be part ofstator wear surface 320, and stator keys 254 may not be worn down bycontact with rotors 42. In various embodiments, a combined thickness T1of stator wear liners 50 and core spine 202 in the axial direction isgreater than a thickness T2 of stator lugs 44 in the axial direction,such that stator wear liners 50 extend beyond stator lugs 44. Thus, bothstator annular ring 252 and stator keys 254 may be a part of a statorwear surface 320 which contacts rotor 42, without rotor 42 contactingstator core 48. The lifetime of stator core 48 may be increased, becausein various embodiments, stator core 48 is not worn down by contact withrotor 42. However, in various embodiments, the thickness of stator lugs44 may be greater than the combined thickness of stator wear liners 50and core spine 202.

Referring to FIG. 4, an exploded view of a rotor 42 is illustratedaccording to various embodiments. Rotor may comprise rotor core 49, androtor wear liner 60. Rotor core 49 may comprise rotor spine 410 androtor lugs 46. Rotor 42 may engage rotor splines 18 in rotor gaps 420formed between rotor lugs 46. Thus, rotor 42 may be rotatable by virtueof the engagement between rotor lugs 46 and rotor splines 18 of wheel10. Similar to stator 40, in various embodiments the material of rotorcore 49 may be selected for its structural properties. For example,rotor core 49 may comprise silicon carbide or titanium. A material ofrotor wear liners 60 may be selected for its frictional properties. Forexample, rotor wear liners 60 may comprise a carbon composite. Thus,rotor 42 may contain the structural advantages of rotor core 49, and thefrictional advantages of rotor wear liners 60. Rotor core 49 may furthercomprise rotor core key notches 430. Rotor core key notches 430 may be arecessed portion of rotor lugs 46. In the illustrated embodiment, rotorcore key notches 430 extend radially all the way through rotor lugs 46,such that rotor lugs 46 have a decreased thickness at rotor core keynotches 430. However, in various embodiments, rotor core key notches 430may only partially extend radially through rotor lugs 46, such thatrotor lugs 46 comprise a substantially uniform thickness at an outersurface of rotor lugs 46.

Rotor wear liner 60 may comprise rotor annular ring 450 and rotor keys440. Rotor keys 440 may be sized and shaped to fit into rotor core keynotches 430. Rotor wear liner 60 may comprise any number of rotor keys440. For example, in the illustrated embodiment, rotor wear liner 60comprises nine rotor keys 440. However, in various embodiments, rotorwear liner 60 may comprise any number of rotor keys 440, for example,rotor wear liner 60 may comprise three rotor keys 440, or twenty rotorkeys 440. In various embodiments, rotor keys 440 and rotor annular ring450 may comprise a single continuous component. However, in variousembodiments, rotor keys 440 may be coupled to rotor annular ring 450. Asillustrated, rotor keys 440 may have a thickness in the axial, or “z”direction which is less than a thickness of rotor annular ring 450.However, in various embodiments, the thickness of rotor keys 440, may besubstantially the same as or greater than the thickness of rotor annularring 450.

Referring to FIG. 5, an assembled rotor 42 is illustrated according tovarious embodiments. Rotor 42 comprises a rotor wear liner 60 coupled toeach side of a rotor core 49. A mating surface of rotor wear liner 60opposite a rotor wear surface 530 may be bonded to rotor core 49. Invarious embodiments, rotor wear liners 60 may be coupled to rotor core49 by a plurality of rivets 510 and cover plates 520. The rivets 510 mayextend through cover plates 520, rotor keys 440, and rotor lugs 46. Invarious embodiments, the rotor keys 440 may not be part of rotor wearsurface 530 of the rotor wear liners 60. Thus, regardless, of how muchthe rotor wear liners 60 wear down, rivets 510 will not change thefrictional properties of rotor 42. During braking, rotor wear surface530 may contact stator wear surface 320, which may create the frictionnecessary to decelerate the aircraft, In various embodiments, rotor wearliners 60 may be bonded to rotor core 49. However, in variousembodiments, rotor wear liner 60 may be floating, such that rotor wearliner 60 is positioned adjacent to rotor core 49 without being fastenedto each other.

Referring to FIG. 6, a rotor 600 is illustrated according to variousembodiments. Rotor 600 may comprise a wear liner 610 with a plurality ofrotor keys 620. Rotor 600 may further comprise a core with a rotor spineincluding a plurality of rotor lugs 630. The plurality of rotor keys 620may be positioned within a plurality of rotor core key notches whichpartially extend into the plurality of rotor lugs 630. In response topressure from disk brake system 20, a shear three may be applied to wearliner 610. However, rotor keys 620 may engage rotor lugs 630, preventingwear liner 610 from rotating with respect to the core.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the inventions. The scope of the inventions is accordinglyto be limited by nothing other than the appended claims, in whichreference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.Different cross-hatching is used throughout the figures to denotedifferent parts but not necessarily to denote the same or differentmaterials.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “one embodiment”, “an embodiment”, “anexample embodiment”, etc., indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but everyembodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. After reading the description, it will be apparent to oneskilled in the relevant art(s) how to implement the disclosure inalternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112, sixth paragraph, unless the element isexpressly recited using the phrase “means for.” As used herein, theterms “comprises”, “comprising”, or any other variation thereof, areintended to cover a non-exclusive inclusion, such that a process,method, article, or apparatus that comprises a list of elements does notinclude only those elements but may include other elements not expresslylisted or inherent to such process, method, article, or apparatus.

What is claimed is:
 1. A stator comprising: a core comprising: a spine;an inner core having a thickness greater than the spine; a lug in theinner core; and a key notch recessed into a radially outer portion ofthe inner core, wherein the core is a single integral componentcomprising the spine, the inner core, and the lug; and a first wearliner coupled to the spine, the first wear liner comprising an annularring and a stator key, wherein the stator key mates with the key notchin the inner core.
 2. The stator of claim 1, further comprising a secondwear liner coupled to the spine opposite the first wear liner.
 3. Thestator of claim 2, wherein a combined thickness of the first wear liner,the spine, and the second wear liner is greater than the thickness ofthe inner core.
 4. The stator of claim 1, wherein the first wear linercomprises a coned disc shape.
 5. The stator of claim 1, wherein thefirst wear liner is at least one of bonded to the core and riveted tothe core.
 6. The stator of claim 1, wherein the core comprises a firstmaterial, the first wear liner comprises a second material, and whereinthe first material is different than the second material.
 7. The statorof claim 1, wherein the stator key engages a core key in the inner coreto prevent rotation of the first wear liner.
 8. The stator of claim 1,wherein the first wear liner comprises a first remanufactured wear linerbonded to a second remanufactured wear liner.
 9. A friction diskcomprising: a core comprising a spine and a plurality of lugs, theplurality of lugs having a plurality of notches recessed in a radiallyouter portion of the plurality of lugs, the plurality of lugs having athickness greater than a thickness of the spine, wherein the core is asingle integral component comprising the spine and the plurality oflugs; and a wear liner comprising a wear surface, a mating surface, anda plurality of keys located adjacent to at least one of an inner surfaceand an outer surface of the wear liner, wherein the plurality of keysare located within the plurality of notches.
 10. The friction disk ofclaim 9, wherein the wear liner is coupled to the core by at least oneof a bond and a rivet.
 11. The friction disk of claim 9, wherein thewear liner comprises a substantially uniform thickness.
 12. The frictiondisk of claim 9, wherein the friction disk comprises at least one of arotor and a stator in an aircraft brake.